I had similar conditions to yours a few years ago. You can get the resistance values of the temp sensor by doing a search here. Its the 4 pin one at the rear of the head.
Are your plugs the correct non resistor type?
My rough running was a combination of wrong plugs, some vac leaks and distrubutor fuzzing up. all at various times making it hard to pin down. Ensuring I used non resistor plugs cured the dizzy cap fouling up. Dont accept the "thats what the books says" answer that the parts shop man/kid gives you. Get a bosch H8DCO or NGK BP6EFS.